I'm looking for data for the 338BR, aka 338 Whisper made from the 7BR case, shooting a 300 gr SMK at about 1050 fps from a 16" barrel. I've looked everywhere I can think of and only found 1 load. Is this cartidge available in quickload?

Try using the 388 mag loads -10% and work up, that's a bloody short barrel mate only good for short range stuff If it were me I'll be pissen the thing off and stick to a reg. cal. what are you using it for, sounds like a pussie round, go a 375 H&H and enjoy....Les

Les, Les, Les,
The 338 Whisper is designed to be subsonic. It was developed for quietly blowing the heads off of sentries when spec ops troops need that capability. Not exactly pussy work......
JCN

Les, I have a 338 Lapua for the extra punch. The 338 Whisper shooting the 300 gr MK at 1050 fps will sound like a pellet gun when using a suppressor, has 734 ft lbs of muzzle energy, and is still going 928 fps and has 574 ft lbs of energy left at 500 yards. The 16" barrel is sufficient to get the needed velocity without going through all the extra paper work and expense of a short barreled rifle. The one load I found was a petite 12.3 gr N350 and it attained the 1050 fps mark in a 12" barrel. It'll be mainly used for coyote hunting. I'm tired of calling in several yotes at once and only getting the first one.